Johns Hopkins researchers have identified a rare gene mutation in a single family with a high rate of schizophrenia, adding to evidence that abnormal genes play a role in the development of the disease. The researchers, in a report published in the journal Molecular Psychiatry, say that family members with the mutation in the gene Neuronal PAS domain protein 3 (NPAS3) appear at high risk of developing schizophrenia or another debilitating mental illnesses.